#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/wait.h>

void writer(int wfd)
{
    const char* str = "hello father,i am child";
    char buffer[128];
    int cnt=0;
    pid_t pid = getpid();
    while (1)
    {
        snprintf(buffer,sizeof(buffer),"message:%s,pid:%d,count:%d",str,pid,cnt);
        write(wfd,buffer,strlen(buffer));
        cnt++;
        sleep(1);
    }
    
}
void reader(int rfd)
{
    char buffer[1024];
    while(1)
    {
        ssize_t n = read(rfd,buffer,sizeof(buffer)-1);
        (void)n;
        printf("father get a message:%s\n",buffer);
    }
}

int main()
{
    int pipefd[2];
    int n = pipe(pipefd);
    if(n<0)
    {
        return 1;
    }
    printf("pipefd[0]:%d,pipefd[1]:%d\n",pipefd[0],pipefd[1]);
    pid_t id = fork();
    if(id==0)
    {
        close(pipefd[0]);
        writer(pipefd[1]);
        exit(0);
    }

    close(pipefd[1]);
    reader(pipefd[0]);
    wait(NULL);
    return 0;
}